The biology and behavior of the codling moth, Cydia pomonella (L.), was studied to
determine factors responsible for differences in susceptibility to moth damage among apple
and pear cultivars.
In release experiments, codling moth adults were intercepted in significantly greater
numbers in host (apple, pear) than in non-host (maple) trees,...
Variable area surveys are used in large geographic regions to estimate the density of birds distributed over a region. If some birds go undetected, a measure of the effective area surveyed, the amount of area occupied by the birds detected, is needed. The effective area surveyed is determined by observational,...
Since the passage of the Education for All Handicapped Children Act in 1975, a number of common problems have emerged. Primarily they involve the difficulties both experienced and created by public schools attempting to fulfill the federal mandate to provide students with disabilities an appropriate public education. The purpose of...
A “smart” tracer is a tracer that provides, directly or through measurement of its concentration or in combination with another compound, at least one “bit” more of information about the environment through which it travels than a conservative tracer. In this study we propose and present the chemical compound resazurin...
The hyporheic zone is of great interest for stream ecologists because of its role in stream biogeochemical processing. Our study addresses the effects of leaf-litter inputs and varying discharge on surface–hyporheic water exchange and their possible consequences for the hyporheic zone biogeochemistry. Our study was conducted during autumn in Riera...
After three decades of active research coupling hydrology and stream ecology, the connection among solute transport, metabolism and processing is still unresolved. These knowledge gaps obscure the functioning of stream ecosystems and how those ecosystems interact with other landscape processes. We must resolve these challenges to wisely manage water resources,...
Small hydropower plants divert part of the water from wide and physically complex
stream channels with active hyporheic areas to narrow and hydraulically simple concrete canals,
and thus, might affect nutrient dynamics. We compared nutrient uptake in diversion canals and
in stream channels in the Leitzaran Stream (Basque Country, northern...
Water transient storage zones are hotspots for metabolic activity in streams although the contribution of different types of transient storage zones to the whole-reach metabolic activity is difficult to quantify. In this study we present a method to measure the fraction of the transient storage that is metabolically active (MATS)...
Quantification of the transient storage zone (A[subscript s]) has become critical in stream biogeochemical studies addressed to examine factors controlling nutrient uptake. It is expected that higher A[subscript s] may enhance the interaction between nutrients and biota and thus, increase nutrient uptake. However, results from the literature are controversial. We...
We propose the experimental use of resazurin (Raz) and develop a metabolically active transient storage (MATS) model to include processes that may provide additional information on transient storage from a biogeochemical perspective in stream ecosystems. Raz is a phenoxazine compound that reduces irreversibly to resorufin (Rru) in the presence of...
This study examined the effect of increasing in-channel leaf standing stocks on hydrologic transient storage and nutrient retention in a Mediterranean mountain stream. A flood at the end of the leaf fall period provided the opportunity to examine the effect of abrupt removal of much of the leaf material. Twenty-one...
In a set of streamside mesocosms, stream ecosystem respiration (ER) increased with biofilm biomass and flow heterogeneity (turbulence) generated by impermeable bed forms, even though those bed forms had no hyporheic exchange. Two streamside flumes with gravel beds (single layer of gravel) were operated in parallel. The first flume had...
IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores...
Moisture has long been identified as one of the major
limiting factors in the distribution of agricultural land use practices.
However, the importance of any environmental element can only be
determined by considering how it is affected by its relationship with
other elements of the environment. Thornthwaite's moisture index
attempts...
Hydrothermal vents appear to be the tip of the subsurface biosphere in the ocean crust. The primary prducers in this biosphere are prokaryotes that tolerate a wide variety of physical and chemical conditions and are versatile in their use of inorganic compounds to drive metabolism. A synthesis of chemical and...
Pallidosis is a disease of strawberry identified in 1957 with an unknown etiology. Two previously uncharacterized viruses in strawberry, Strawberry pallidosis associated virus (SPaV) and Beet pseudo-yellows virus (BPYV), have been found associated with disease symptoms. The complete nucleotide sequence of both viruses was determined and molecular detection protocols developed....
This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with height; and compensatory mechanisms that mitigate height-related growth constraints. Height-related trends in foliar physiological and anatomical characteristics were examined both within trees as well...